High resolution depth images of earth subsurface layers are important for reservoir exploration, delineation, and development. Wave equation based seismic depth migration techniques, such as reverse time migration (RTM), are suitable techniques for seismic depth imaging in the oil industry, especially in complex environments such as subsalt exploration. However, RTM is a computationally intensive process that requires propagating waves in 2D or 3D models using time or frequency domain wave equation solvers.